1. Field of the Invention
The present invention relates to a ventilation system for a car window.
2. Description of the Related Art
As a known car window ventilation system of such a type, there have been a detachable car ventilation system in which a window panel integrally molded from plastics, or the like, and having a plurality of ventilating holes is put between a door sash frame and an upper end edge of window glass in a car so that natural ventilation to let fresh air in is performed (JP-A-2-220924); a car window ventilation system in which an exhaust fan is merely provided in a slight gap between a door sash frame and an upper end edge of window glass in a car (JP-U-6-55818); and so on.
These car window ventilation systems are, however, of the type in which a window panel is put between a door sash frame and an upper end edge of window glass in a car so that four sides of the window panel are not adjustable. Hence, there is a defect that the systems lack applicability to windows different in size and shape and to different types of cars. Furthermore, air exhausting only by means of a fan without use of natural ventilation to let fresh air in involves a defect that the capacity of ventilation is often insufficient.
In any of the related art, known ventilation systems, the ventilating member is constituted by a single layer filter. Hence, there is an inconvenience of invasion of dust or rainwater. Furthermore, the known ventilation systems were configured so as to be easily subjected to mischief from the outside. In addition, there was a risk that something might be thrown into the car from the outside through such airflow holes because of the shape of airflow holes in the related-art ventilating members.